Normally, the lungs are kept inflated within the chest cavity by negative pressure in the pleural spaces. A lung will partially or completely collapse if air and/or blood collects in the pleural space, thus causing loss of negative pressure (termed pneumothorax and/or hemothorax respectively). The most dangerous type of these conditions is tension pneumothorax (i.e. pressure pneumothorax or valve pneumothorax) and/or, less commonly, tension hemothorax. In this case, the lung not only fully collapses, but the air and/or fluid within the pleural space builds up enough pressure in the chest cavity to cause a significant decrease in the ability of the body's veins to return blood to the heart, which can result in cardiac arrest and death unless treated emergently.
Tension pneumothorax and/or hemothorax is the second leading cause (33%) of potentially preventable combat deaths and constitutes around 5% of all fatal military injuries. In addition to penetrating and blast trauma, tension pneumothorax can also occur from other forms of barotrauma, such as high pressures during mechanical ventilation, underlying lung disease (e.g. asthma, emphysema, blebs), changes in environmental pressure (e.g. hyperbaric treatment, high-altitude, rapid ascent from scuba diving), and/or Cardio-Pulmonary Resuscitation (CPR). Studies on ICU deaths show rates of undiagnosed tension pneumothorax ranging from 1.1% to 3.8%, with increased risk for patients who had ventilation or cardiopulmonary resuscitation. Early diagnosis and swift treatment of tension pneumothorax and/or hemothorax, by relieving the pressure in the pleural space, is critical for patient survival. However, correct diagnosis of this condition is far from guaranteed during emergencies. Presentation of the classic signs and symptoms are highly variable and, in many cases, the time and/or treatment environment does not permit diagnostic confirmation by chest x-ray, ultrasound, or other means. Thus, current treatments may be withheld due to fear of causing patient harm or, conversely, may be inadvertently performed on a healthy lung and worsen the patient's condition.
Traditional treatment, especially in the out-of-hospital emergency arena, is to place a wide-bore needle and plastic cannula into the chest cavity to release pressure (i.e. “needle thoracostomy” or “chest decompression”). For example, current Tactical Combat Casualty Care guidelines recommend the consideration of this “needle decompression” in casualties with chest trauma and progressive respiratory distress. Simple wide-bore needles for this use are widely available commercially. Examples include standard IV catheters in various sizes (e.g. from BD Angiocath™) and the “H&H Tension Pneumothorax Needle” from H&H Associates, Inc. However, although standard needle decompression is an effective treatment for pressure buildup, it has multiple disadvantages. Such treatment results in lung compromise, as an open passage is left in the chest wall producing a non-tension open pneumothorax; possible iatrogenic injury to the lung or heart, from introduction of the sharp needle tip; the necessity of all patients having subsequent tube thoracostomy (a major procedure), upon presentation to a higher level of care; and, inability to perform the technique bilaterally, without subsequent continuous positive pressure ventilation (because both lungs are deflated).
Some authors have discussed solutions for individual improvements upon this simple needle thoracostomy technique, including the use of a syringe filled with sterile saline attached to the cannula or the “hanging drop” technique to help confirm pleural penetration; an Asherman chest seal to stabilize the cannula and provide a check valve; or, the attachment of a flutter valve to the cannula to decrease the chances of iatrogenic pneumothorax (e.g. Cook® Emergency Pneumothorax, Pre-Hospital Emergency Pneumothorax, and Spec Ops Emergency Pneumothorax Sets). However, these advances all have individual drawbacks, take additional steps and equipment, and are not common in actual use.
The literature discloses various additional known methods and devices related to the treatment of tension pneumothorax and/or hemothorax.
For example, U.S. Pat. No. 2012/0051967 A1 to Murphy et al describes a battlefield needle container for carrying a standard needle to be used for treating tension pneumothorax and/or hemothorax. However, this device has no improvements upon the needle device itself.
U.S. Pat. No. 5,478,333 to Asherman, Jr. discloses a medical dressing for treatment of open chest injuries. The device consists of a dressing made of pliable plastic placed over an open wound, having a check valve to allow built up pressure to vent. Similar devices and procedures are set forth in U.S. Pat. No. 7,429,687 B2 to Kauth et al, U.S. Pat. No. 7,615,674 B2 to Asherman, and 2011/0054340 to Russ et al. Although these and similar works are capable of preventing the conversion of an open pneumothorax to a tension pneumothorax, all such devices are incapable of treating a closed tension pneumothorax, as they have no means to penetrate the chest and allow the built up pressure to vent. Additionally, when used over a standard needle, they have multiple disadvantages including a multi-step process, which at the minimum results in a transient open pneumothorax, as well as the lack of any documentation means.
U.S. Pat. No. 4,164,938 to Higaki, et al describes a simple one-stage device for the diagnosis of tension pneumothorax. This work describes a standard needle attached to a balloon; when inserted into the pleural space, the balloon inflates if there is increased pressure, transiently indicating tension. However, although this medical pressure-gauge device can diagnose tension pneumothorax, it is not a treatment device as no air (besides that inside the balloon) is actually released from the body. Additionally, it has the added disadvantage of a sharp distal needle end, which may potentially injure the lung.
U.S. Pat. No. 4,153,058 to Nehme discloses a pleural decompression catheter for releasing entrapped air within a human body. The device consists of an elongated prong inserted into the chest, having a passage for establishing communication from the pleural space, through a one-way balloon valve, to the external environment. Once the device is inserted into the patient, the trocar is removed to release trapped air. However, this device, as well as a similar one disclosed in U.S. Pat. No. 4,664,660 to Goldberg et al, has numerous disadvantages for the emergent treatment of tension pneumothorax and/or hemothorax. The size and complexity of these devices render them ill-suited for use in emergency situations. Additionally, both devices are placed over a trocar, necessitating a multi-step process for treatment. They additionally have no means to affix to the patient, in case of transport, and have no documentation means, to alert later caregivers that tension had (or had not) previously been present. Additionally, both have sharp distal ends which may injure the lung upon initial placement, especially if a pneumothorax and/or hemothorax was incorrectly diagnosed.
U.S. Pat. No. 7,229,433 to Mullen describes an apparatus specifically for treating pneumothorax and/or hemothorax. This involves the introduction of a catheter with a check valve over a large trocar obturator unit, along with a means of securely affixing the catheter to the patient. However, this device has similar disadvantages, including the risk of lung injury upon introduction of the trocar into the chest cavity, especially if a pneumothorax and/or hemothorax was incorrectly diagnosed. Furthermore, the device requires a multi-step process for treatment (adding complexity and delay) and lacks a diagnostic documentation indicator to alert current and later caregivers of the diagnosis.
U.S. Pat. No. 6,402,770 to Jessen describes a method and apparatus for placing a tube into the body that can also be used for the treatment of pneumothorax and/or hemothorax. It utilizes a cam action dual-blade thoracostomy device that additional has a check valve component. However, this device has the disadvantage of possible injury to the chest wall neurovascular structures, the lung, and other organs through the use of moving blades. It also lacks a diagnostic documentation indicator.
Similarly, U.S. Pat. Application No. 2008/0312638 and U.S. Pat. No. 8,057,443 B2 to McNeil describe an apparatus for withdrawing fluid and/or air from a space in the body that could be used for treatment of tension pneumothorax. The work includes a catheter that is placed over a hollow needle into the pleural space with means for affixing said device to the patient and withdrawing air and/or fluid. However, this device has similar disadvantages for the emergency treatment of pneumothorax and/or hemothorax, including the aforementioned disadvantages to Mullen's as well as the lack of an automatic check valve.
Similarly, U.S. Pat. No. 4,944,724 to Goldberg, et al describes an apparatus for locating a body cavity having a fluctuating fluid pressure, such as fluid in the pleural space. The work includes a catheter that is placed over a hollow trocar with a pressure bubble indicator, to allow for visualization of changes in pressure while placing the needle, and a means for affixing the device to the patient. However, the apparatus is not fashioned specifically for the emergent treatment of tension pneumothorax and/or hemothorax, and thus has multiple disadvantages for this indication. The device overall is bulky and requires a multi-step introduction of a sharp trocar, which may potentially injure the lung. Furthermore, its indicator is transient and does not leave stable documentation of tension for later caregivers to view.
Additionally, U.S. Pat. No. 6,770,070 to Balbierz describes a method and apparatus for the prevention of pneumothorax during lung biopsy, which can seal lacerations in the lung. However, this device is not for the emergent treatment of tension pneumothorax and/or hemothorax.
Also known in the art are “Veress” or “Veress-type” needles, which have an outer needle having a sharp distal end and an inner probe with a blunt distal end that extends through the outer needle. In Veress needles, the inner probe is biased to force the blunt distal end of the probe beyond the sharp distal end of the outer needle. This then prevents injury to internal organs (e.g. lung). However, when the blunt distal end of the probe encounters dense material (e.g. chest wall), the probe is forced backward, and the sharp end of the needle is presented so that it can puncture the dense material.
Most Veress needles in the art describe use primarily for abdominal laparoscopic procedures, such as U.S. Pat. Nos. 5,376,082; 5,207,647; 5,514,111; 5,827,221; and 6,221,048 to Phelps; U.S. Pat. No. 5,660,883 to Scarfone, et al; 2009/0005800 to Franer et al, and U.S. Pat. No. 5,098,388 to Kulkashi et al. These are not adapted for the emergent treatment of pneumothorax and/or hemothorax and thus have multiple disadvantages in being modified to do so, including being overly large and bulky for emergency use, lacking an automatic check valve to prevent introduction of external air, and the absence of a documentation indicator to alert later caregivers that tension of pneumothorax and/or hemothorax had previously been treated and thus necessitating further care.
Similarly, U.S. Pat. No. 5,421,821 to Janicki et al describes a Veress needle system and method for insufflating the abdominal cavity prior to laparoscopic surgery. This system includes an electronic sensor to detect negative pressure and indicate when the surgeon enters the abdominal cavity. However, this device is not adapted for the emergent diagnosis and treatment of pneumothorax and/or hemothorax. It lacks an automatic check valve to prevent introduction of external air and has no means to affix to the device to the patient. Additionally, the electronic pressure indicator described only indicates negative (not positive “tension”) pressure and is a transient (not stable) indicator.
U.S. Pat. No. 5,300,046 to Scarfone, et al; U.S. Pat. No. 5,997,486 to Burek, et al; and, U.S. Pat. No. 5,725,506 to Freeman, et al describes similar devices and methods for thoracentesis; a Veress needle inserted into the pleural space is used to introduce a catheter for drainage. Although these devices could be used to relieve a tension pneumothorax, they have multiple disadvantages in the emergent setting including the need for a multi-step process requiring withdrawal of the needle from a catheter and the lack of a stable documentation indicator, to alert later caregivers that tension pneumothorax and/or hemothorax had previously been treated thus necessitating further care.
U.S. Pat. No. 5,334,159 to Turkel describes a Veress thoracentesis needle having a direct passageway through the needle for withdrawing fluid (no overlying catheter) and an automatic check valve to prevent introduction of air into the pleural space. Although this device is a significant improvement over prior art, it is fashioned for standard pleural fluid withdrawal, not for the emergent treatment of tension pneumothorax and/or hemothorax. Thus it has multiple disadvantages in being used for the later indication in the emergency arena. This includes the absence of a diagnostic documentation indicator to alert later caregivers that a tension pneumothorax had been treated prior to arrival. If this device was used in an out-of-hospital emergency (e.g. in an ambulance or battlefield), the only way of knowing that a tension pneumothorax had been treated would be by the out-of-hospital provider hearing a short “whish” of air out of the needle, something that can be very subjective and difficult to hear in a loud out-of-hospital environment with possible sirens and/or gunfire. Thus, without the stable indicator, each patient that had needle decompression performed in the field (whether or not they truly had a tension pneumothorax at that time) would likely need a full chest tube thoracostomy upon arrival to higher care. This is because both patients who actually had a tension pneumothorax and those who had been misdiagnosed could both have the same diagnostic findings upon later chest x-ray or ultrasound (i.e. a (re)inflated lung due to the automatic check valve venting air). Thus, it is dangerous to remove the device without placing a full chest tube as tension pneumothorax could rapidly return.
Turkel also describes no means to affix the device to the patient, to ensure that the catheter is not prematurely removed. Although not necessary for simple in-hospital thoracentesis as described in the work, a sturdy means of affixing the device to the patient is critical in the emergent arena (both in- and out-of-hospital), when the patient may be undergoing rapid transport and/or significant other movement, such as from concurrent Cardio-Pulmonary Resuscitation (CPR) or surgery.
Additionally, Turkel describes subsequent modifications in U.S. Pat. No. 5,685,852, which is a similar Veress device modified for use as an epidural needle. This device has an indicator to allow visualization of the rotation of the needle, but if used for the treatment of tension pneumothorax and/or hemothorax would have similar disadvantages as aforementioned.
U.S. Pat. No. 6,447,483 to Steube, et al is a Veress thoracentesis needle similar to that of Turkel, with an improved hyper-sensitive detection mechanism for sensing when the blunt portion of the Veress is in contact with the lung. For the emergency treatment of tension pneumothorax and/or hemothorax, it has the same disadvantages as described for Turkel.
Similar to Turkel and Steube, thoracentesis Veress-type needles with one or more automatic check valves are available commercially. These include the “Toramatic” devices (e.g. 1-55, 1-80, 1-VER) from Bioservice S.p.A. and Medax Medical Devices, “Safe-T-Centesis® Catheter Drainage System” from CareFusion, and the “Pleura-safe® Safety Thoracentesis Needle” from Allomed Medtech GmbH. However, for the emergency treatment of tension pneumothorax and/or hemothorax, these have the same disadvantages as already described for Turkel and Steube.
Regardless of use, the Veress needle assemblies of the art have not before been modified specifically for the emergent treatment of tension pneumothorax and/or hemothorax. Indeed, no Veress needle assemblies described have been used with a stable documenter to indicate a positive diagnosis for tension. Additionally, no method has to date been described for the safe treatment of tension pneumothorax and/or hemothorax using a device that simultaneously or near-simultaneously stably documents and treats the life-threatening process, with minimal risk to misdiagnosed patients. As such, there is a need for an emergency device and method to do so.
Each of the patents and published patent applications mentioned above are hereby incorporated by reference.